Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina

Autores
Zárate, Marcelo Arístides; Blasi, Adriana Mónica
Año de publicación
1991
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The Late Pleistocene and Holocene loess deposits of the SE Buenos Aires province are composed of four allostratigraphic units that represent four episodes of loess deposition. The first and the second episodes occurred in Late Pleistocene times. The second episode was followed by a soil forming interval (Early Holocene to Mid-Holocene times). The third episode took place at about 5000 yr BP, after the Holocene sea-level maximum when marine regression began. The fourth episode constitutes a historical event of only local significance. Loess shows a fairly constant granulometric and mineralogical composition. The modal fraction consists of very fine sand and coarse silt (3 to 5 phi). They are classified as sandy silts or silty sands. Three grain-size subpopulations are differentiated: coarse, medium and fine. The medium-size subpopulation, which is the most important, consists of most of the very fine sand and coarse silt. It is thought to be transported by modified saltation and short-term suspension during local dust-storms. The mineralogical composition of loess consists of a volcaniclastic assemblage derived mainly from reworked pyroclastic deposits, primary tephras and volcaniclastic sediments. The source area of these materials was located in the lower Colorado river valley about 400 km SW of the studied area. There was also a direct supply by volcanic ash falls.
Facultad de Ciencias Naturales y Museo
Materia
Geología
Holocene
Tephra
Late Pleistocene
Volcaniclastic
Coarse silt
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/139235

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network_name_str SEDICI (UNLP)
spelling Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, ArgentinaZárate, Marcelo ArístidesBlasi, Adriana MónicaGeologíaHoloceneTephraLate PleistoceneVolcaniclasticCoarse siltThe Late Pleistocene and Holocene loess deposits of the SE Buenos Aires province are composed of four allostratigraphic units that represent four episodes of loess deposition. The first and the second episodes occurred in Late Pleistocene times. The second episode was followed by a soil forming interval (Early Holocene to Mid-Holocene times). The third episode took place at about 5000 yr BP, after the Holocene sea-level maximum when marine regression began. The fourth episode constitutes a historical event of only local significance. Loess shows a fairly constant granulometric and mineralogical composition. The modal fraction consists of very fine sand and coarse silt (3 to 5 phi). They are classified as sandy silts or silty sands. Three grain-size subpopulations are differentiated: coarse, medium and fine. The medium-size subpopulation, which is the most important, consists of most of the very fine sand and coarse silt. It is thought to be transported by modified saltation and short-term suspension during local dust-storms. The mineralogical composition of loess consists of a volcaniclastic assemblage derived mainly from reworked pyroclastic deposits, primary tephras and volcaniclastic sediments. The source area of these materials was located in the lower Colorado river valley about 400 km SW of the studied area. There was also a direct supply by volcanic ash falls.Facultad de Ciencias Naturales y Museo1991info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf211-220http://sedici.unlp.edu.ar/handle/10915/139235enginfo:eu-repo/semantics/altIdentifier/issn/0343-2521info:eu-repo/semantics/altIdentifier/issn/1572-9893info:eu-repo/semantics/altIdentifier/doi/10.1007/bf00186018info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-03T11:04:13Zoai:sedici.unlp.edu.ar:10915/139235Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-03 11:04:13.48SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
title Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
spellingShingle Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
Zárate, Marcelo Arístides
Geología
Holocene
Tephra
Late Pleistocene
Volcaniclastic
Coarse silt
title_short Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
title_full Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
title_fullStr Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
title_full_unstemmed Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
title_sort Late pleistocene and holocene loess deposits of the Southeastern Buenos Aires province, Argentina
dc.creator.none.fl_str_mv Zárate, Marcelo Arístides
Blasi, Adriana Mónica
author Zárate, Marcelo Arístides
author_facet Zárate, Marcelo Arístides
Blasi, Adriana Mónica
author_role author
author2 Blasi, Adriana Mónica
author2_role author
dc.subject.none.fl_str_mv Geología
Holocene
Tephra
Late Pleistocene
Volcaniclastic
Coarse silt
topic Geología
Holocene
Tephra
Late Pleistocene
Volcaniclastic
Coarse silt
dc.description.none.fl_txt_mv The Late Pleistocene and Holocene loess deposits of the SE Buenos Aires province are composed of four allostratigraphic units that represent four episodes of loess deposition. The first and the second episodes occurred in Late Pleistocene times. The second episode was followed by a soil forming interval (Early Holocene to Mid-Holocene times). The third episode took place at about 5000 yr BP, after the Holocene sea-level maximum when marine regression began. The fourth episode constitutes a historical event of only local significance. Loess shows a fairly constant granulometric and mineralogical composition. The modal fraction consists of very fine sand and coarse silt (3 to 5 phi). They are classified as sandy silts or silty sands. Three grain-size subpopulations are differentiated: coarse, medium and fine. The medium-size subpopulation, which is the most important, consists of most of the very fine sand and coarse silt. It is thought to be transported by modified saltation and short-term suspension during local dust-storms. The mineralogical composition of loess consists of a volcaniclastic assemblage derived mainly from reworked pyroclastic deposits, primary tephras and volcaniclastic sediments. The source area of these materials was located in the lower Colorado river valley about 400 km SW of the studied area. There was also a direct supply by volcanic ash falls.
Facultad de Ciencias Naturales y Museo
description The Late Pleistocene and Holocene loess deposits of the SE Buenos Aires province are composed of four allostratigraphic units that represent four episodes of loess deposition. The first and the second episodes occurred in Late Pleistocene times. The second episode was followed by a soil forming interval (Early Holocene to Mid-Holocene times). The third episode took place at about 5000 yr BP, after the Holocene sea-level maximum when marine regression began. The fourth episode constitutes a historical event of only local significance. Loess shows a fairly constant granulometric and mineralogical composition. The modal fraction consists of very fine sand and coarse silt (3 to 5 phi). They are classified as sandy silts or silty sands. Three grain-size subpopulations are differentiated: coarse, medium and fine. The medium-size subpopulation, which is the most important, consists of most of the very fine sand and coarse silt. It is thought to be transported by modified saltation and short-term suspension during local dust-storms. The mineralogical composition of loess consists of a volcaniclastic assemblage derived mainly from reworked pyroclastic deposits, primary tephras and volcaniclastic sediments. The source area of these materials was located in the lower Colorado river valley about 400 km SW of the studied area. There was also a direct supply by volcanic ash falls.
publishDate 1991
dc.date.none.fl_str_mv 1991
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/139235
url http://sedici.unlp.edu.ar/handle/10915/139235
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0343-2521
info:eu-repo/semantics/altIdentifier/issn/1572-9893
info:eu-repo/semantics/altIdentifier/doi/10.1007/bf00186018
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
211-220
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instname:Universidad Nacional de La Plata
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instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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